The present invention relates to a tone generator device having a function of driving light emitting elements, a portable (or mobile) phone using the tone generator device, and a method for driving the light emitting elements for such a tone generator device or portable phone. The present invention also relates to a portable phone having a function of displaying information of a caller (call originator) via light emitting elements in response to receipt of an incoming call, and a method for driving the light emitting elements for that purpose.
Heretofore, techniques have been developed for varying a light emission pattern of an LCD (Liquid Crystal Display) backlight in synchronism with an incoming-call signaling melody (also known as a ringer melody) of a portable phone; one example of such techniques is disclosed in Japanese Patent Application Laid-open Publication No. 2001-211237. With the techniques, users of portable phones can not only identify arrival of an incoming call visually as well as auditorily, but also enjoy viewing the light emission pattern.
However, the above techniques, in accordance with which a CPU (Central Processing Unit) detects a musical scale of a ringer melody to control the light emission of the LCD backlight, is disadvantageous in that great burdens are imposed on the CPU. The techniques are also unsatisfactory in that the display tends to be very monotonous, because the light emission pattern is only varied in synchronism with the detected musical scale of the ringer melody and the ringer melody and the light emission pattern correspond to each other on a one-to-one basis.
Further, when the portable phone has received an incoming call, it has been necessary to confirm the phone number or name of the caller displayed on the LCD display device, in order to identify the caller. More sophisticated technique has been known, for example, from Japanese Patent Application Laid-open Publication No. HEI-9-238178 or HEI-11-004282, which permits each caller to be identified auditorily. More specifically, ringer melodies and expected callers are registered in memory in association with each other, and when an incoming call has been received, one of the registered ringer melodies, corresponding to the caller, is sounded to allow the user to auditorily identify the caller.
However, such caller identification by the ringer melody is also disadvantageous in that it can not be used in a quiet environment where loud sounds should not be produced.